Hot-water storage heater



p 1945. E. R. KOPl =EL 2,385,450

HOT WATER STORAGE HEATER Filed May 24, 1943 5 Sheets-Sheet 1 ms RKoppel 'INVENTOR.

ATTORNEY Sept. 25, 1945. E. R. KOPPEL HOT WATER STORAGE HEATER Filed May 24, 1943 3 Sheets-Sheet 2 Ernsz ma 1e! INVENTOR BY f ATTORNEY.

Sept. 25, 1945.

E. R. KOPPEL HOT WATER STORAGE HEATER Filed May 24, 1943 3 Sheets-Sheet 3 ATTORNEY:

Patented Sept. 25, 1945 HOT-WATER STORAGE HEATER Ernst B. Koppel, Milwaukee, Wis., assignor to A. 0. Smith Corporation, Milwaukee, Wis., a

corporation of New York Application May 24, 1943, Serial No. 488,143

8 Claims.

This invention relates to hot water storage heaters of the gas fired or fuel heated type having a storage tank above a burner, and a flue for conducting the products of combustion from the burner to a. chimney or the like.

The construction heretofore employed for domestic water heaters had, in the case of heaters with a central flue, the flue extending upwardly through the tank and through the top of the outer casing, with a so-called draft hood or flue cap ventilator disposed on top of the flue to connect the same to a chimney pipe. This draft hood, which acts as a back-draft device and is necessary for draft control and safety, was disposed entirely oultside the heater casing for free access of air thereto. In the case of heaters with an external flue, a similar hood was located outside the heater relative to the outlet of the flueways.

The objects of the present invention are to enable the employment of more eflicient draft hoods, prevent spillage of gas from the draft hood, protect the draft hood from distortion and displacement, reduce the over-all height of the heater, in the case of external flues to reduce the temprature of the top cover of the heater casing, and to provide a heater having a neater appearance than heretofore.

Other objects and advantages will appear hereinafter in the description of certain embodiments of the invention illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a side elevation of a water heater partly in section;

Fig. 2 is an enlarged transverse horizontal section taken on line 22 of Fig. 1, a portion being broken away;

Fig. 3 is an enlarged detail transverse vertical section through the top portion of the water heater;

Fig. 4 is a view similar to Fig. 3 illustrating a modified form of construction;

Fig. 5 is a similar view illustrating a floating type of tank with an external flue and central hood;

Fig. 6 is a similar view illustrating an external flue with the hood at one side; and

Fig. 7 is a sectional view similar to a part of the lower end of Fig. 1 showing the heater for Figs. 5 and 6.

In carrying out the invention the draft hood is disposed inside the casing and between the top of the tank and the top of the casing, and the casing has lateral openings for receiving outside air. The structure provides a secondary chamber for supplying air to the draft hood and avoiding the ill effects of external currents of air.

Referring to the drawings, the water heater shown in Fig. 1 has a cylindrical tank I, an outer casing 2 surrounding the same, and a burner 3 disposed beneath the tank and inside the casing at the bottom. The heater is supported on a base 4 which rests on the floor and provides suitable inlets for air to the burner.

A central flue 5 extends upwardly through the tank and through a layer of heat insulation 6 disposed on the upper head I of the tank. Similar heat insulation is disposed throughout the radial space between the side walls of the tank and the casing. A thin covering 8 of sheet metal or of a nonmetallic material of low heat conductivity lies on top of insulation 6 and may be supported on the top edge of the tank I. The covering 8 has an opening at its center for receiving the flue 5 and it extends outwardly to the outer casing 2 of the heater.

A draft hood 9 is either supported on .the upper end of the flue or otherwise located relative to it. as shown in Fig. 3, and consists of an outer bell-shaped member ID having an open bottom of substantially larger diameter than that of the flue 5, and an open top of about the same diameter as the flue for receiving the first joint of a chimney pipe ll, shown in dash lines. A deflector cone [2 is supported in inverted position over the top end of the flue by means of three legs l3 which are welded to the inside of the member ID and extend downwardlyto engage the inside walls of flue 5 with a slight spring action to locate the hood on the flue. Outwardly extending lugs H on legs l3 rest on the upper edge of the flue and serve to support the hood 9 thereon.

The deflector I2 is spaced from the flue to allow the escape of the products of combustion from the latter into the member Ill. The deflector I2 is also spaced from the outer member I to provide for the passage of the products of combustion upwardly around the deflector and out of the upper end of member l0 into chimney H.

The parts of the draft hood 9 are generally of ordinary construction, except that with the use of the present invention it is possible to utilize larger openings for the admission of air to the hood and for [the passage of gases around the deflector therein without increasing the danger of spillage of combustion gases and without increasing the over-all height of the heater. This enables the obtaining of greater efflciencies from the draft hood which will operate satisfactorily with a greatly reduced length of pipe I I.

The top of casing 2 comprises a sheet metal head l5 curved in streamline appearance with a downward flange H5 at its outer perimeter overlapping and encircling the upper end of the cylindrical body of the casing. The flange I 6 has a series of openings l1 therein around, or partially around, the circumference and above the upper end of the cylindrical body of the casing. In the making of certain of these openings II the metal is struck inwardly to provide a substantially horizontal flange or lug i8 at predetermined locations around the perimeter of head l5 to support the same on covering 8 or upon the upper end of the body of easing 2. At the same time these lugs will hold cover 8 in place.

The head I5 has a central opening of a diameter to receive the upper end of the hood member ID, and adjacent the edge of the opening the head maybe formed to substantially correspond with the shape of member ID. An insulating washer i9 may be disposed between the head l5 and member ID to prevent heat transference to the cover I 5 with the concurrent possibility of discoloration of the paint, and at the same time hold the hood 9 from becoming displaced. The hood 9 extends upwardly through head IE only a sufficient distance to provide the proper connection with chimneyl The openings I! bear a definite relationship in size to the passages between the deflector I 2 and the member ID of the draft hood. In practice it has been found preferable to make the openings I! total in cross-section about the same as the cross-section of the passage in the hood. In this way any undue currents of air in the basement or room where the heater is located will not cause spillage of burner gases. The chamber 20 disposed inside the casing head (5 and around the hood 9 provides a source of quiet air for efflcient operation of the draft hood at 'all times ber 20 constitutes a secondary baflie. In the case of a heater with an external flue, this chamber 20 provides at the same time added insulation preventing excessive temperatures of the casing head l5 which are often encountered otherwise with this type of heater.

The Hood 9 is protected by the outer casing from becoming jammed on the flue 5 or displaced relative thereto in handling or shipment so that the proper relationship between the deflector I 2 and the flue is maintained.

In the modification illustrated in Fig. 4, the hood 9' is constructed entirely as a part ofthe head I5 and supported by it above the end of the flue 5. In this construction the head i5 is flanged upwardly around the hood and welded to the member ID. The deflector I2 is supported by horizontal radial strips 21 formed integrally therewith and In the modification illustrated in Fig. 5 and Fig. 7 the tank 22 is of the floating type with a surrounding flue 23 disposed between it and the insulation 24. The insulation extends over the top of the flue to provide a, central opening above which the draft hood 25 is located. I The top cover 26 of the outer casing is constructed similarly to that of Figs. 1 to 3 and has similar peripheral welded to the member in.

openings 21. A secondary air chamber 28 exists between the insulation 24 and cover 26.

The modification illustrated in Fig. 6 is similar to that of Fig. 5 with the exception that the draft hood 25' is located at the rear of the tank, permitting a lower top cover 26' with the insulation 24' extending up to the cover. The secondary chamber 28 encircles the hood 25' and has a large lateral opening 29 to the outside air through casing 30.

The invention may have various embodiments within the scope of the accompanying claims.

I claim:

1. In a domestic water heater, a vertically disposed cylindrical tank having a burner below for heating the same and a central flue extending upwardly therethrough for conducting the products of combustion from said burner to a chimney, an outer casing for said tank with heat insulation between said tank and said casing, and a draft hood for said flue between the upper end of said flue and the top of said casing, said casing having openings therein, the combined area of said openings substantially equaling the area of the opening of said draft hood to provide outside air thereto.

2. In a domestic water heater, a vertically disposed cylindrical tank having a burner below for heating the same and a central flue extending upwardly therethrough for conducting the products of combustion from said burner to a chimney, an outer casing for said tank with heat insulation between said tank and said casing, and a draft hood for said flue between the upper end of said flue and the top of said casing, said casing having openings therein, the combined area of said openings substantially equaling the area of the opening of said draft hood, and the top of said casing being spaced from said insulation to provide a I secondary chamber above said heat insulation and surrounding said hood for supplying air to said draft hood and preventing spillage of the products of combustion therefrom.

3. In a domestic water heater, a vertically disposed cylindrical tank having a burner below for heating the same and a flue extending upwardly from said burner for conducting the products of combustion from said burner to a chimney, an outer casing for said tank with heat insulation between said tank and said casing, and a draft hood for said flue supported on the upper end thereof and enclosed by the top of said casing, said casing having openings therein for the entrance of outside air and being spaced from said insulation to provide a secondary chamber above said tank and surrounding said hood.

4. In a domestic water heater, a vertically disposed cylindrical tank having a burner below for heating the same and a central flue extending upwardly therethrough for conducting the products of combustion from said burner to a chimney, an outer casing for saidtank with heat insulation between said tank and said casing, and a draft hood secured in the top of said casing spaced from and above the upper end of said flue for mixing the products of combustion with air and conducting the same to a chimney, said casing having openings in its outer circumference for conducting air to said hook and providing a secondary air chamber above said tank and surrounding said hood.

5. In a domestic water heater, a vertically disposed cylindrical tank, a burner below said tank for heating the same, an outer casing for said tank with heat insulation for preventing heat loss, a flue for conducting the products of combustion upwardly from the burner and transferring the heat to the contents of the tank, and a draft hood for said flue beneath the top of said casing, said casing having at least one opening therein adjacent the top for the entrance of outside air and providing a secondary chamber surrounding said hood.

6. In a domestic water heater, a vertically disposed cylindrical tank having a burner below for heating the same, an outer casing for said tank with heat insulation for preventing heat loss, a fine encircling the tank between the walls thereof and said insulation for conducting the products of combustion from said burner upwardly in contact with said tank walls, and a draft hood for said flue beneath the top of said casing, said casing having openings therein adjacent the top for the entrance of outside air and providing a secondary chamber surrounding said hood.

'7. In a domestic water heater, a vertically disposed cylindrical tank, a burner below said tank for heating the same, an outer casing for said tank with heat insulation for preventing heat loss,

a flue encircling the tank between the walls thereof and said insulation for conducting the products of combustion from said burner upwardly in contact with said tank walls, and a draft hood disposed at one side of said casing beneath the top thereof for receiving the products of combustion from said flue and conducting the same upwardly through said casing top to a chimney pipe, said casing having a lateral opening therein adjacent said draft hood and having a space therein free of insulation and adjacent said hood to provide a secondary chamber for supplying air to said hood.

8. In a device of the class described, a casing, a burner disposed at the bottom thereof, an outlet opening at the top thereof, a flue for conducting the products of combustion from the burner to said outlet opening, a draft hood disposed in said flue adjacent the outlet opening and inside said casing, said casing being spaced from said draft hood to provide a secondary chamber surrounding said draft hood, and said casing having an opening therein for supplying said secondary chamber with outside air.

ERNST R. KOPPEL. 

